[jeffbee]

Indeed, a trumpet has one slide for tuning only and two more slides that are used while playing, so it's not even technically correct.

[bluGill]

Your trumpet maybe, but my trumpet from 1957 only has tuning slides, which cannot be used while playing.

[jeffbee]

Interesting. A student horn I guess? I've never owned one that didn't have at least a third valve slide ring. I think they were widespread around the time that the trumpet really took over from the cornet, around 1900-1920. My pre-War Olds has moving slides.

[bluGill]

I know a few cases where slides were added later. I don't know when they became common but impression is layer.

[Polizeiposaune]

Yep. A basic trumpet has more slides than a basic trombone.